From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F1F7851C071; Wed, 30 Sep 2026 17:30:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790789421; cv=none; b=Tm+pbGXwOu/pxbop4Cm9yB3DuO/dnbsTas3d5TzUO/KKQGxbC9RFR0p06vcbkYWYPGvfSqHczk5TqmSwqxV4Ws0fBf97TrPy0uJQEdkP8e8dCmK8McSrgtMdUdlcaFx+yhJPDymUjS/zWYOkoOd48BDTfVaDi06t1LE+eqTPqC0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790789421; c=relaxed/simple; bh=GmTi5/L5TCnlpAQHD/OF1ENdJHtpf4eCiZBYp8TC3No=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ugcKL4JBLYS8GX18jfrS0cTEo9O/TNqm9jxKWM9+0/8cFV6/v5IU4Wx+EzVaqoEy/eX9x84cZzsO6GAiNDulm5jiHy4b/oB8iDWFv5VWYIeXumWCBV7c3QM/KO6FwC1Yvo3bBaF6IiMsOWJGzUnR/ALk1kYAR4d+ob/Nxj4t2Gg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mxSaPIyJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mxSaPIyJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56A6D1F000FF; Wed, 30 Sep 2026 17:30:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790789419; bh=gcSlemA53kGY/Aq83eTYoq8mBKg2Q79b4a1yKnYu/mA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mxSaPIyJScQsYssK/zA2D43qxuK2+xYreuWee05rejjcVD9QhD/EjbGiS1Yb/0k2C dECXGqi/km5gIQ9F6YBl2lTzjfx9YwDUS07WgihmCeujO0HCKL3OW1vap/p6LqfbFU bSyXYY8zcviKUVFGyAmBYHJ2Y7Yu/C/SY/fXGHnw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Fan Wu Subject: [PATCH 6.12 471/877] ipe: protect the dm-verity root hash with RCU Date: Wed, 30 Sep 2026 17:23:02 +0200 Message-ID: <20260930152424.839500357@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152414.738996857@linuxfoundation.org> References: <20260930152414.738996857@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fan Wu commit 2776e9c28513a1c855a94792b292cbcc533418c8 upstream. ipe_bdev_setintegrity() frees the old root hash when dm-verity publishes a new one on ->preresume, while policy evaluation can still be dereferencing it. Protect the root hash with RCU. The evaluation path already runs under rcu_read_lock(). Fixes: e155858dd995 ("ipe: add support for dm-verity as a trust provider") Cc: stable@vger.kernel.org Assisted-by: LLM [FW: remove model name according to latest guideline] Signed-off-by: Fan Wu Signed-off-by: Greg Kroah-Hartman --- security/ipe/eval.c | 12 ++++++++---- security/ipe/eval.h | 2 +- security/ipe/hooks.c | 22 +++++++++++++++++----- 3 files changed, 26 insertions(+), 10 deletions(-) --- a/security/ipe/eval.c +++ b/security/ipe/eval.c @@ -134,10 +134,14 @@ static bool evaluate_boot_verified(const static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, struct ipe_prop *p) { - return !!ctx->ipe_bdev && - !!ctx->ipe_bdev->root_hash && - ipe_digest_eval(p->value, - ctx->ipe_bdev->root_hash); + const struct digest_info *root_hash; + + if (!ctx->ipe_bdev) + return false; + + root_hash = rcu_dereference(ctx->ipe_bdev->root_hash); + + return root_hash && ipe_digest_eval(p->value, root_hash); } #else static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, --- a/security/ipe/eval.h +++ b/security/ipe/eval.h @@ -27,7 +27,7 @@ struct ipe_bdev { #ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE bool dm_verity_signed; #endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */ - struct digest_info *root_hash; + struct digest_info __rcu *root_hash; }; #endif /* CONFIG_IPE_PROP_DM_VERITY */ --- a/security/ipe/hooks.c +++ b/security/ipe/hooks.c @@ -9,6 +9,7 @@ #include #include #include +#include #include "ipe.h" #include "hooks.h" @@ -204,7 +205,20 @@ void ipe_bdev_free_security(struct block { struct ipe_bdev *blob = ipe_bdev(bdev); - ipe_digest_free(blob->root_hash); + ipe_digest_free(rcu_access_pointer(blob->root_hash)); +} + +static void ipe_set_dmverity_roothash(struct ipe_bdev *blob, + struct digest_info *info) +{ + struct digest_info *old; + + /* Protected by device-mapper's md->suspend_lock */ + old = rcu_replace_pointer(blob->root_hash, info, true); + if (old) { + synchronize_rcu(); + ipe_digest_free(old); + } } #ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE @@ -252,8 +266,7 @@ int ipe_bdev_setintegrity(struct block_d return -EINVAL; if (!value) { - ipe_digest_free(blob->root_hash); - blob->root_hash = NULL; + ipe_set_dmverity_roothash(blob, NULL); return 0; } @@ -273,8 +286,7 @@ int ipe_bdev_setintegrity(struct block_d info->digest_len = digest->digest_len; - ipe_digest_free(blob->root_hash); - blob->root_hash = info; + ipe_set_dmverity_roothash(blob, info); return 0; err: